DESCRIPTION: One of the greatest barriers to obtaining useful results in epidemiologic studies is the lack of adequate exposure data. The broad, long term objective of the proposed project is to improve the assessment of pesticide exposures in epidemiologic studies which will allow for the identification of health risks such as cancer, which would otherwise not be found using traditional methods of exposure assessment. This study has been designed to evaluate total body dose of the cornmonely used pesticides MCPA, niecoprop, dicamba, cyfluthrin and imidacloprid (using biological urine monitoring) in professional turf applicators. Previously developed dose prediction models will be validated (mecoprop, dicamba) and adjusted, if necessary to improve dose prediction. The important exposure variables or predictor variables which will be effective in predicting total body dose in applicators without the use of biological samples, will be evaluated and this information will be used to determine exposure reduction strategies. Prior to the initiation of a full-scale field study, a comprehensive evaluation of the urinary excretion of MCPA, cyfluthrin and imidacloprid will be conducted on a group of 10 workers. In the second year of the study, a sample of 100 workers employed by TruGreen Chemlawn will be selected from approximately 5 different franchises and information concerning the use patterns of pesticides for each individual employee will be obtained. The total amount of each pesticide excreted in the urine will be measured for two consecutive 24 hour periods following a minimum of three work days. This process will be repeated three times: a spring evaluation of herbicide exposures; a summer evaluation of insecticide exposure; and a fall evaluation of herbicide exposure. During each sampling period, information will be obtained from each applicator on spraying practices, hygiene practices, and other variables which may affect their daily exposure to herbicides. Current pesticide use reported by the applicators will be compared with actual use data obtained from employer records. A previously developed quantitative exposure prediction model that is based on use records and other predictor variables will be validated, and, based on the newly collected data, new models will be developed in order to better predict pesticide exposures if deemed necessary. Recommendations, based on questionnaire and modeling data, to reduce exposure to these pesticides, will be developed and provided to the participating company and subjects. In the short term, this type of research can be used to reduce pesticide exposures by identifying cost-effective controls in both occupational and environmental settings and this, in the long term, may help to reduce both acute and chronic health risks.